Demographics of CF sputum donors. In total, 11 sputum samples were collected from 7 female and 4 male patients, one of whom was African American. The remaining 10 were Caucasian. Mean patient age was 28.5 years, ranging from 18-46 years of age. Spirometry data were obtained for each patient at the time of sample collection. The mean FEV1 % predicted value was 48.8 ranging from normal (90% predicted) to severely impaired (24% predicted) lung function. Additionally mean FVC was 2.7 L, and mean FEF25-75 was 0.96. Values of pH, % solids, and mean complex viscosity (η*) were also obtained for each sputum sample. Mean pH was 7.1 within a narrow range (6.3-7.7), mean % solids was 5.6 and the mean η* was 2.5 Pa·s. Sputum was collected from patients with CF according to UNC IRB protocol #15-2431.